Potato

The potato is a starchy, tuberous vegetable that originally comes from the Americas and serves as a basic food source worldwide. It grows as an underground stem tuber on the plant *Solanum tuberosum*, a perennial member of the nightshade family, Solanaceae.

Wild potato species are found from the southern United States down to southern Chile. Genetic evidence indicates that all cultivated potatoes trace back to a single origin in what is now southern Peru and extreme northwestern Bolivia, where they were domesticated roughly 7,000 to 10,000 years ago from a species within the *S. brevicaule* complex. In the Andes region of South America, where the plant is native, numerous varieties are still grown.

The Spanish brought potatoes to Europe from the Americas in the latter half of the 16th century. Today, they are a staple food across much of the globe and a key part of the world's food supply. Over centuries of selective breeding, more than 5,000 different varieties have emerged. Europe, particularly its northern and eastern parts, still has the highest per capita potato production, while the fastest growth in production during the 21st century has occurred in southern and eastern Asia. As of 2023, China and India lead the world in potato output.

Like tomatoes and other nightshades, the potato belongs to the genus *Solanum*. The plant’s above-ground parts contain the toxin solanine. Normal, properly stored potato tubers produce only negligible amounts of glycoalkaloids, but if tubers are exposed to light, their sprouts and skins can become toxic.

**Etymology** The English word "potato" comes from the Spanish *patata*, which itself derives from the Taíno word *batata*—meaning "sweet potato," not the plant now called potato. The term "spud" for a potato dates to the 15th-century word *spudde*, which referred to a short, stout knife or dagger, likely related to the Danish *spyd* (spear). By around 1840, the general sense of something short and thick had been transferred to the tuber.

**Description** Potato plants are herbaceous perennials that reach about one meter (three feet) in height. Their stems are hairy, and the leaves typically have roughly four pairs of leaflets. Flowers can be white, pink, blue, or purple, with yellow centers, and are pollinated by insects. The plant forms tubers to store nutrients; these are not roots but stems that develop from thickened rhizomes at the tips of long, thin stolons. On the tuber’s surface are "eyes," which protect the vegetative buds from which new stems grow. These eyes are arranged in a spiral pattern. Tubers also have small breathing holes called lenticels, which are circular and vary in number depending on tuber size and environmental conditions. Tuber formation is triggered by decreasing day length, though this tendency has been reduced in commercial varieties. After flowering, the plant produces small green fruits resembling cherry tomatoes, each containing about 300 tiny seeds.

**Phylogeny** Potatoes, like tomatoes, belong to the genus *Solanum* within the nightshade family (Solanaceae), a diverse group of often poisonous flowering plants that includes mandrake, deadly nightshade, and tobacco. The most commonly cultivated potato is *S. tuberosum*, a tetraploid with 48 chromosomes, and modern varieties of this species are the most widely grown. Other cultivated species include four diploid species (24 chromosomes): *S. stenotomum*, *S. phureja*, *S. goniocalyx*, and *S. ajanhuiri*; two triploid species (36 chromosomes): *S. chaucha* and *S. juzepczukii*; and one pentaploid species (60 chromosomes): *S. curtilobum*. Within tetraploid *S. tuberosum* there are two major subspecies. The Andean potato, *S. tuberosum andigena*, is adapted to the short-day conditions of its mountainous equatorial and tropical home. The Chilean potato, *S. tuberosum tuberosum*, native to the Chiloé Archipelago, is adapted to the long-day conditions of southern Chile’s higher latitudes. A 2025 study by Zhang et al. examining *Solanum* genomes groups all potato species under *S. tuberosum*. This study indicates that the Petota (potato) lineage includes more than 55 diploid species, with only one selected by humans for domestication; it posits that all landraces branch from a single point within *Solanum candolleanum*.

**History**

**Domestication** Wild potato species range from the southern United States to southern Chile. The potato was first domesticated in southern Peru and northwestern Bolivia by pre-Columbian farmers near Lake Titicaca, around 7,000 to 10,000 years ago, from a species in the *S. brevicaule* complex. The earliest archaeologically verified potato tuber remains were found at the coastal site of Ancon in central Peru, dating to 2500 BC. The most widely cultivated variety, *Solanum tuberosum tuberosum*, is native to the Chiloé Archipelago and was cultivated by local indigenous people before the Spanish conquest.

**Spread** After the Spanish conquest of the Inca Empire, the Spanish introduced the potato to Europe in the latter half of the 16th century as part of the Columbian exchange. European mariners—possibly including those of the Russian-American Company—later carried the staple to territories and ports worldwide, especially their colonies. European and colonial farmers were initially slow to adopt potato farming. After 1750, however, potatoes became an important food staple and field crop, playing a major role in Europe’s 19th-century population boom.